Sinn Féin leader Mary Lou McDonald has raised Dáil questions about the funding for and motivation behind a special information supplement about the Irish national flag.

Ms McDonald argued that the supplement with the Irish Independent yesterday carried photographs of Ceann Comhairle Seán Ó Fearghaíl, and Fianna Fáil senator Mark Daly, who is an advocate for respecting the national flag.

"I want to know if public moneys were used for this? It is an extraordinary publication. It is very lengthy and, in part, informative," Ms McDonald said.

"On the face of it, this supplement is about the national flag, Thomas Meagher and so forth, all of which is good. However, it becomes difficult when it can be interpreted as politically partisan," Ms McDonald added.

She was speaking during a renewed discussion on the controversy surrounding the Government's Strategic Communications Unit.

Ms McDonald suggested that Fianna Fáil was as good as Taoiseach Leo Varadkar at garnering publicity.

The Ceann Comhairle insisted his office had not contributed any money to the supplement.

He went on to say he would happily put that in writing to comply with a demand from the Sinn Féin leader.

This is a special group which honours the 19th-century patriot who introduced the green, white and orange national flag.

The foundation chairman, Rev Michael Cavanagh, also a Church of Ireland clergyman, has issued the following brief statement, insisting no taxpayers' money whatsoever was involved in the supplement and an accompanying exhibition in the GPO in Dublin.

"The national flag belongs to everyone and the supplement was produced to ensure that every generation, especially students, know the Irish flag's meaning for peace.

"The foundation received no public funds to install the first ever exhibit in the history of the State on the Irish flag and its meaning for peace and its creator Thomas F Meagher in the GPO. Nor did it receive public funding for the 24-page supplement in the Irish Independent," Rev Cavanagh said.

The patriot's own words say: "The white in the centre signifies a lasting truce between orange and green."